AS OF 954 AM EDT THURSDAY...QUICK MORNING UPDATE TO SYNC GRIDS IN
WITH RADAR/SATELLITE TRENDS. HAVE WARM FRONT MOVING ACROSS ERN NY
TOWARD THE CHAMPLAIN VALLEY AT THIS TIME. ELEVATED INSTABILITY IS
RESULTING IN A FEW TSTMS. THIS PRECIP SHOULD PUSH INTO ERN VT BY
16Z. LOOKS LIKE A BIT OF A BREAK IN THE PRECIP AFTERWARD...HOWEVER
AS THE CLOUDS BREAK UP DAYTIME HEATING WILL START TO WORK ITS
MAGIC. UPSTREAM SOUNDINGS SHOWING A BIT OF A CAP...BUT ONCE WE HIT
M-U 70S THAT SHOULD BE BROKEN. LOCAL WRF RUNS INDICATE CONVECTIVE
INITIATION ABOUT 17Z ACROSS WRN NY STATE AND THAT SEEMS REASONABLE.
UPSTREAM SOUNDINGS AND LATEST 12Z NAM JUST COMING IN ARE SHOWING
DECENT INSTABILITY AND SHEAR. POCKET OF DRY AIR ALOFT WILL ENHANCE
CHANCE FOR STRONG WIND GUSTS. ALSO SMALL CONCERN OF SUPERCELL
DEVELOPMENT DUE TO LOW LEVEL SOUTHERLY WINDS (PRIMARILY TERRAIN
DRIVEN IN THE VALLEYS) WITH SW/W WINDS ALOFT. FEEL A HIGH
LIKLIHOOD THAT A SVR TSTM WATCH WILL BE NEEDED BY EARLY AFTERNOON
FOR MUCH OF THE AREA. DOESNT APPEAR TO BE A HIGH END WIDESPREAD SVR
EVENT TYPE OF DAY...BUT STILL A FEW STORMS WILL GO SEVERE AND WE
WILL BE MONITORING RADAR CLOSELY THIS AFTN.
AS OF 146 PM EDT THURSDAY...UPDATED FCST TO INCLUDE SVR
THUNDERSTORM WATCH NUMBER 587 FOR CPV...SLV AND NORTHERN DACKS.
LATEST SFC ANALYSIS SHOWS WEAK BOUNDARY APPROACHING SLV
ATTM...WITH SFC BASED CAPE VALUES BTWN 1800-2200 J/KG. LOOPING VIS
SATL PICS SHOWS A WEAK CYCLONIC CIRCULATION JUST NORTH OF LAKE
ONTARIO MOVING TWD OUR FA. THIS ENHANCED LIFT AND INCREASING
AMOUNTS OF INSTABILITY WL HELP IN THE DEVELOPMENT OF SHOWERS AND
STORMS. BOTH WRF 4KM/12KM WRF AND RUC13 SHOWS PRECIP AND COMPOSITE
REFLECTIVITY ENHANCEMENTS ACRS THIS REGION BY 19Z TODAY. THIS
ACTIVITY WL CONTINUE TO TRACK EAST INTO THE DACKS BY MID AFTN AND
CPV BY 5PM. STILL SOME QUESTIONS WITH REGARDS TO AREAL COVERAGE
AND INTENSITY OF STORMS...DUE TO LARGE DRY LAYER BTWN
700-500MB...WHICH IS DEPICTED NICELY IN THE WATER VAPOR LOOP.
OTHERWISE...EXPECT SOME ENHANCED LLVL SHEAR DUE TO SOUTHERLY FLW
UP THE CPV LATER THIS AFTN...WHICH COULD HELP WITH STORM
ORGANIZATION AND SOME WEAK MID/UPPER LVL ROTATION...ESPECIALLY
ACRS ADDISON/RUTLAND COUNTIES. WL CONT TO MONITOR RADAR TRENDS FOR THE
EXPECTED INCREASE IN AREAL COVERAGE/INTENSITY OF STORMS OVER THE
NEXT 1 TO 2 HRS. IT SHOULD BE A BUSY AFTN AND EARLY EVENING ACRS
OUR FA.
AS OF 340 PM EDT THURSDAY...REST OF THIS AFTERNOON MESOSCALE
DISCUSSION: CRNT RADAR SHOWS AREAL COVERAGE/INTENSITY OF STORMS
INCREASING ACRS THE SLV AND NORTHERN DACKS...STILL JUST BELOW SVR
LIMITS. LAPS SOUNDINGS SHOW CAPE PROFILES OF 2000 TO 2500 J/KG...VERY
SIMILAR TEMP AND MOISTURE PROFILES. MEANWHILE...AT THE SFC LLVL
BOUNDARY IS JUST ENTERING SLV ATTM WITH SOME CONVERGENCE NOTED...
WHICH SHOULD ENHANCE LLVL LIFT. AS STORMS MOVE ACRS THE DACKS AND
INTO THE CPV...EXPECT OVERALL COVERAGE/INTENSITY TO INCREASE. LAPS
AND RUC DATA SHOWS SFC BASED CAPES AROUND 2000 J/KG ASSOCIATED WITH
TEMPS IN THE L80S AND SFC DWPTS IN THE MID 60S AT BTV. THIS COMBINED
WITH ENHANCED 0-1KM SHEAR FROM SOUTHERLY FLW VEERING QUICKLY TO
THE SOUTHWEST AT 85H WL HELP IN DEVELOPING ORGANIZED STORMS WITH
SOME ROTATION. FURTHERMORE...LATEST RUC AND LAPS 0-3KM VGP SHOWS
AXIS OF 0.25 TO 0.35 DEVELOPING ACROSS THE CENTRAL/SOUTHERN CPV
BTWN 20Z-22Z. THIS INDICATES GOOD SHEAR AND CAPE PARAMETERS WL BE
PRESENT. WL CONT TO MONITOR RADAR THIS AFTN...BUT STILL THINK
LARGE DRY LAYER WL LIMIT THE OVERALL AREAL COVERAGE OF CONVECTION.